Improvement in dies for forming screw-threads



F. RHIND.

Patented June 22, 7875.

ENVENTBR:

TNESEEB.

THE GRAPH"; C(LPHOTO LITH.39& 41 PARK PLACEJLY.

.drical opening of the die B.

Unrrnn STATES FRANK RHIND,

AND CLOCK COMPANY, OF

error- Parent or BROOKLYN, new YORK, Assrenon To BRISTOL BRASS BRISTOL, CONNECTICUT.

Specification forming part of Letters Eatent No. 164,764, dated June 522, 1875;

application tiled January 13, 1875.

To all whom it may concern:

Be it known that I, FRANK RHIND, of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Dies for Forming Screw-Threads; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being bad to the accompanying drawings, which form part of this specification.

My invention relates to an improvement in dies for the purpose of stamping screw-threads upon metallic collars for lamps and other articles, as will be more fully described hereafter. The accompanying drawings represent my invention.

A represents a steel block, with a circular cavity, a, narrowing toward the bottom. Into this cavity is placed the die 13, which consists of three parts, C, which may be taken apart, to allow the collar, which is placed over it, to be taken out after it has been stamped. On the inside of the upper part of the cylindrical opening in the center of this die B is a screwthread, I), which corresponds to another screwt-hread, e, upon the outside of the upper part of the die E, which has its place in the cylin- The die E consists of four parts, two of which, (I, occupy, at opposite sides of the circumference, nearly onehalf each of the space, leaving between them two vacant places opposite to each other, to be filled by the pieces g. The four pieces (1 g are pivoted at the bottom G, so that they may be made to incline inward toward the central opening 0, left open for the introduction of a steel wedge, F.

When the collar is placed over the die 13, its inside, upon which the scrcw-threzul is to be stamped, will be found between the screwthreadsupon the dies B and E, the latter of which, having movable sides, will yield inward, so as to make the placing and removing of the collar easy. The steel wedge, having been placed in the center of the die E, is now forced downward, whereby the parts of I, and 1G provided with screw-threads are brought to bear upon that part of the. collar placed be tween them upon which the impression is to be made. o

By thus stamping the threads, not only can lighter or thinner metal be used, but the whole operation is performed much more quickly and cheaply than heretofore.

Having thus described my invention, 1' claim--.

1. The combination of the recessed block A, divided dies 13 and E, and wedge F, substantially as shown.

2. The die E, formed in four pieces, all of which are pivoted so as to close inward, substantially as described.

In testimony that I claim the foregoing I have hereunto set my hand.

FRANK RHIND.

Witnesses:

JAMES C. CLoYD, lIORA'ilO 1*. Avnn'iLL. 

